<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="https://cdn.jsdelivr.net/npm/vue@2.7.14/dist/vue.js"></script>
</head>
<body>
    <div id="app">
    <button v-on:click="fu">切换显示与隐藏</button>
    <p v-show="flag">黑马程序员</p>
    </div>
</body>
<script>
   const app=new Vue({
    el:'#app',
    data:{
        message:"hello",
        count:666,
        flag:false,
    },
    methods:{ 
            fu(){
                this.flag=!this.flag
            }  
        }
   })
</script>
</html>